The surest thing at the coming Olympic Games in London — more than the swimmer Michael Phelps, or the sprinter Usain Bolt, or even the American men’s basketball team — may be a 23-year-old Japanese gymnast nicknamed Superman. Four years ago, at the Beijing Games, Kohei Uchimura finished second in the men’s all-around competition, based on his performance in floor exercise, pommel horse, rings, vault, parallel bars and horizontal bar. Since then Uchimura has won three consecutive world championships in the event, something no other male gymnast has done. And he didn’t just edge his way to those golds by hundredths or tenths of a point; he won by overwhelming, multiple-point margins. (In 2009 and 2011, he finished first in four of the six disciplines.) “After he competes in London,” says Tim Daggett, an Olympic gold medalist in gymnastics and a commentator for NBC, “I think he’ll have enough titles . . . to say he’s the greatest that ever lived.”

For Daggett, precision sets Uchimura — his first name Kohei means peaceful flight — apart. “A lot of gymnasts are colorful, aggressive, dynamic — but they don’t have the look that he has,” Daggett says. “His legs are always pencil straight, his toes are always perfectly pointed when he’s doing these crazy, crazy things.” As Steve Butcher, who will be the chief judge for the pommel horse in London, puts it, the expectation is that when Uchimura competes, “you’re going to see something amazing.” (Butcher also notes, “The scary thing for his competitors is that he could continue for one or two Olympic Games after London.”)

Uchimura’s dominance, along with the prospects of his team, which is expected to contend for gold, marks a return to form for Japanese gymnastics. The Olympics, and gymnastics in particular, played an important role in the evolution of postwar Japan. In 1961, the Japanese government passed the Sports Promotion Law to prepare the country for the 1964 Olympic Games in Tokyo and advance “the development of a bright and high-quality lifestyle for citizens.” Japan became the “kingdom of gymnastics” when its men won five consecutive team golds in the Olympics and five consecutive world championships between 1960 and 1978.

“Competitive gymnastics suits the Japanese because of its unique importance of repetitive drills that require strong fundamentals,” Tsunekazu Takeda, the president of the Japanese Olympic Committee, says. “Gymnastics has long been established as part of the standard physical-education classes. Almost all students one way or another have experienced horizontal-bar and mat-related exercises.”

But, Daggett says, “they lost their way a little bit, and they were not like they were in the ’60s or ’70s or they are now — that’s the ebb and flow of the athletic world.” Now that flow is back, and Uchimura is on his way to becoming a pop-culture icon. When he revealed during the Beijing Olympics that his precompetition fuel of choice was a chocolate cookie bar called Black Thunder, sales of the snack tripled.

Sweet and likable, he’s a welcome departure from both the wimpy, “herbivorous” man-child stereotype of mid-2000s Japan — Uchimura claims he doesn’t like to eat vegetables — and the conventional image of the stoic, emotionally bottled-up Japanese businessman. “He has that calm, analytical demeanor of today’s youth combined with a core mental strength beyond the willpower and grit of times past,” one fan wrote on Twitter. “He’s more like a samurai than a gymnast.” Yet he never forgets to thank his mom at awards ceremonies. She and his father, Kazuhisa Uchimura, both gymnasts, got Kohei started in the sport at age 3 when they opened a training school near their home outside Nagasaki.

For her part, his mother, Shuko Uchimura, insists that nothing has changed for the family, despite the comparisons to warriors and superheroes, despite her son’s appearances in TV commercials and on the exterior of one of Japan Airlines’s 777s. “He is still just my son, and we have to stay humble,” she says. But she is concerned that too much press coverage about her son’s aversion to vegetables sends the wrong message to his young admirers. “Does he really hate vegetables? That’s a good question. I’m sure he eats them when he needs to. I don’t want kids in Japan to stop eating their veggies just because they think that’s what my son does.”